Tolerance of Hymenaea stigonocarpa Mart. ex Hayne. to glyphosate

Abstract

The objective of this work was to evaluate the glyphosate herbicide effect on Hymenaea stigonocarpa Mart. ex Hayne seedlings. A randomized block design with 5 replicates was used with an experimental unit composed of one H. stigonocarpa plant in 5L pots. The treatments were: 0 (control); 9.6; 240; 480; 960 g a. ha− 1 of glyphosate. Evaluations were performed 24 hours and 60 days after application. Gas exchange, respiration, photosynthesis, visual, anatomical and histochemical evaluations were carried out with leaves from the middle third being collected, and the growth in relation to the two dates was measured and recorded. The growth analysis showed that the seedlings showed an increase in stem diameter, a decrease in leaf number and an increase in height. There were increases in photosynthetic, electron transport and transpiratory rates, and in the effective yield of photosystem II one day after the glyphosate application. The plants then showed a reduction in transpiratory rate and a reduction in Fv/Fm at 60 days after application. With these studies we can conclude that the Hymenaea stigonocarpa species is able to survive after contact with the glyphosate herbicide, with no visual and/or anatomical damage, along with positive increases in growth and physiological characteristics.